Aircraft fuel system with removable fuel tank

Abstract

During a method, an aircraft powerplant is provided. The aircraft powerplant includes an injector and a fuel system configured to deliver fuel to the injector. The fuel system includes a first tank, a first circuit and a second circuit arranged in parallel with the first circuit between the first tank and the injector. The second circuit includes a second tank. The fuel is directed from the first tank to the injector during a first mode through the first circuit and independent of the second circuit. The fuel is directed from the second tank to the injector during a second mode through the second circuit and independent of the first circuit.

What is claimed is: 
     
       1. A method, comprising:
 providing an aircraft powerplant, the aircraft powerplant including an injector and a fuel system configured to deliver a first fuel, a second fuel, or both the first fuel and the second fuel, to the injector, the fuel system including a first tank, a first circuit, and a second circuit arranged in parallel with the first circuit between the first tank and the injector, and the second circuit comprising a second tank and an upstream flow regulator that is upstream of the second tank, wherein an evaporator is positioned downstream from the first tank and upstream from the first circuit and the second circuit, the evaporator configured to convert the first fuel from the first tank from a liquid phase to a gaseous phase, the upstream flow regulator fluidly coupled with the evaporator and configured to receive the first fuel from the evaporator and selectively direct the first fuel to the second tank, and wherein the first circuit is configured such that fuel flowing in the first circuit bypasses the second tank; 
 directing the first fuel from the first tank to the injector during a first mode through the first circuit and independent of the second circuit; and 
 directing the second fuel from the second tank to the injector during a second mode through the second circuit and independent of the first circuit. 
 
     
     
       2. The method of  claim 1 , further comprising directing the second fuel into the second tank from a source external from the fuel system. 
     
     
       3. The method of  claim 1 , further comprising directing the first fuel into the second tank from the first tank during the first mode. 
     
     
       4. The method of  claim 1 , further comprising directing the first fuel into the second tank from the first tank during the second mode. 
     
     
       5. The method of  claim 1 , wherein the first fuel is not directed from the second tank to the injector during the first mode. 
     
     
       6. The method of  claim 1 , wherein the first fuel is not directed to the injector through the first circuit during the second mode. 
     
     
       7. The method of  claim 1 , further comprising:
 exchanging a depleted tank for the second tank; 
 wherein the second tank is filled with the second fuel prior to the exchanging. 
 
     
     
       8. The method of  claim 1 , further comprising:
 removing the second tank from the aircraft powerplant following the directing of the second fuel from the second tank; and 
 replacing the second tank with a replacement tank that is filled with the second fuel. 
 
     
     
       9. The method of  claim 1 , wherein the second fuel comprises hydrogen fuel. 
     
     
       10. The method of  claim 1 , wherein
 the first fuel contained within the first tank is in a liquid phase; and 
 the second fuel contained within the second tank is in a gaseous phase. 
 
     
     
       11. The method of  claim 1 , wherein the aircraft powerplant comprises a turbine engine. 
     
     
       12. The method of  claim 1 , wherein the aircraft powerplant comprises an aircraft propulsion system. 
     
     
       13. The method of  claim 1 , wherein the aircraft powerplant comprises an auxiliary power unit. 
     
     
       14. A method, comprising:
 providing an aircraft including an aircraft powerplant, the aircraft powerplant including an injector and a fuel system configured to deliver a first fuel, a second fuel, or both the first fuel and the second fuel, to the injector, the fuel system including a first tank, a first circuit and a second circuit arranged in parallel with the first circuit between the first tank and the injector, and the second circuit comprising a second tank and an upstream flow regulator that is upstream of the second tank, wherein an evaporator is positioned downstream from the first tank and upstream from the first circuit and the second circuit, the evaporator configured to convert the first fuel from the first tank from a liquid phase to a gaseous phase, the upstream flow regulator fluidly coupled with the evaporator and configured to receive the first fuel from the evaporator and selectively direct the first fuel to the second tank, and wherein the first circuit is configured such that fuel flowing in the first circuit bypasses the second tank; 
 installing a second tank into the second circuit while the aircraft is parked at an airport terminal, wherein the second tank is filled with the fuel in a gaseous phase; 
 directing the first fuel from the first tank to the injector during a first mode through the first circuit and independent of the second circuit; and 
 directing the second fuel from the second tank to the injector during a second mode through the second circuit and independent of the first circuit. 
 
     
     
       15. The method of  claim 14 , further comprising vaporizing the first fuel directed from the first tank to the injector during the first mode. 
     
     
       16. An aircraft powerplant, comprising:
 an engine comprising an injector; and 
 a fuel system configured to deliver a first fuel, a second fuel, or both the first fuel and the second fuel, to the injector, the fuel system including a first tank, a first circuit and a second circuit that is fluidly coupled in parallel with the first circuit between the first tank and the injector, and the second circuit comprising a replaceable second tank and an upstream flow regulator that is upstream of the replaceable second tank, wherein an evaporator is positioned downstream from the first tank and upstream from the first circuit and the second circuit, the evaporator configured to convert the first fuel from the first tank from a liquid phase to a gaseous phase, the upstream flow regulator fluidly coupled with the evaporator and configured to receive the first fuel from the evaporator and selectively direct the first fuel to the replaceable second tank, and wherein the first circuit is configured such that fuel flowing in the first circuit bypasses the replaceable second tank; 
 the fuel system configured to direct the first fuel from the first tank to the injector through the first circuit independent of the second circuit during a first mode; and 
 the fuel system configured to direct the second fuel from the replaceable second tank to the injector through the second circuit independent of the first circuit during a second mode. 
 
     
     
       17. The aircraft powerplant of  claim 16 , wherein the fuel system is configured to provide the first fuel and the second fuel to the injector in the gaseous phase; the first tank is configured to store the first fuel substantially in the liquid phase; and the second tank is configured to store the second fuel substantially in the gaseous phase. 
     
     
       18. The aircraft powerplant of  claim 16 , wherein the first circuit comprises a second flow regulator. 
     
     
       19. The aircraft powerplant of  claim 16 , wherein the second circuit further comprises a second flow regulator fluidly coupled between the second tank and the injector.